beteach (v.)

c. 1200, "to hand over," from be- + take (v.). From the beginning confused in form and sense with the older beteach. From c. 1400 in the etymologically proper sense "to take, accept." Its reflexive sense "take oneself" (to) emerged mid-15c. Related: Betook; betaken.

Middle English tēchen, from Old English tæcan (past tense tæhte, past participle tæht) "to show (transitive), point out, declare; demonstrate," also "give instruction, train, assign, direct; warn; persuade."

This is reconstructed to be from Proto-Germanic *taikijan "to show" (source also of Old High German zihan, German zeihen "to accuse," Gothic ga-teihan "to announce"), from PIE root *deik- "to show, point out." It is related to Old English tacen, tacn "sign, mark" (see token). The notion is "to show how to do something by way of information or instruction." Related: Taught; teaching.

By mid-14c. as "disseminate" a system of belief. By c. 1200 as "indicate" how something is to happen; used by 1560s in threats, "make known to one at a cost."

Enraged lemonade vendor (Edgar Kennedy): I'll teach you to kick me!

Chico: you don't have to teach me, I know how. [kicks him]

["Duck Soup," 1933]

The usual sense of Old English tæcan was "show, declare, warn, persuade" (compare German zeigen "to show," from the same root); while the Old English word for "to teach, instruct, guide" was more commonly læran, source of modern learn and lore.

word-forming element of verbs and nouns from verbs, with a wide range of meaning: "about, around; thoroughly, completely; to make, cause, seem; to provide with; at, on, to, for;" from Old English be- "about, around, on all sides" (the unstressed form of bi "by;" see by (prep.)). The form has remained by- in stressed positions and in some more modern formations (bylaw, bygones, bystander).

The Old English prefix also was used to make transitive verbs and as a privative prefix (as in behead). The sense "on all sides, all about" naturally grew to include intensive uses (as in bespatter "spatter about," therefore "spatter very much," besprinkle, etc.). Be- also can be causative, or have just about any sense required. The prefix was productive 16c.-17c. in forming useful words, many of which have not survived, such as bethwack "to thrash soundly" (1550s) and betongue "to assail in speech, to scold" (1630s).